[NET]: Modify all rtnetlink methods to only work in the initial namespace (v2)

Before I can enable rtnetlink to work in all network namespaces I need
to be certain that something won't break.  So this patch deliberately
disables all of the rtnletlink methods in everything except the
initial network namespace.  After the methods have been audited this
extra check can be disabled.

Changes from v1:
- added IPv6 addrlabel protection

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

4 files changed, 59 insertions, 0 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a70cecf..26de8ee 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2971,11 +2971,15 @@ static const struct nla_policy ifa_ipv6_policy[IFA_MAX+1] = {
 static int
 inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
+	struct net *net = skb->sk->sk_net;
 	struct ifaddrmsg *ifm;
 	struct nlattr *tb[IFA_MAX+1];
 	struct in6_addr *pfx;
 	int err;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
 	if (err < 0)
 		return err;
@@ -3028,6 +3032,7 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags,
 static int
 inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
+	struct net *net = skb->sk->sk_net;
 	struct ifaddrmsg *ifm;
 	struct nlattr *tb[IFA_MAX+1];
 	struct in6_addr *pfx;
@@ -3037,6 +3042,9 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	u8 ifa_flags;
 	int err;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
 	if (err < 0)
 		return err;
@@ -3310,26 +3318,42 @@ done:
 
 static int inet6_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	enum addr_type_t type = UNICAST_ADDR;
+
+	if (net != &init_net)
+		return 0;
+
 	return inet6_dump_addr(skb, cb, type);
 }
 
 static int inet6_dump_ifmcaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	enum addr_type_t type = MULTICAST_ADDR;
+
+	if (net != &init_net)
+		return 0;
+
 	return inet6_dump_addr(skb, cb, type);
 }
 
 
 static int inet6_dump_ifacaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	enum addr_type_t type = ANYCAST_ADDR;
+
+	if (net != &init_net)
+		return 0;
+
 	return inet6_dump_addr(skb, cb, type);
 }
 
 static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr* nlh,
 			     void *arg)
 {
+	struct net *net = in_skb->sk->sk_net;
 	struct ifaddrmsg *ifm;
 	struct nlattr *tb[IFA_MAX+1];
 	struct in6_addr *addr = NULL;
@@ -3338,6 +3362,9 @@ static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr* nlh,
 	struct sk_buff *skb;
 	int err;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
 	if (err < 0)
 		goto errout;
@@ -3555,11 +3582,15 @@ nla_put_failure:
 
 static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	int idx, err;
 	int s_idx = cb->args[0];
 	struct net_device *dev;
 	struct inet6_dev *idev;
 
+	if (net != &init_net)
+		return 0;
+
 	read_lock(&dev_base_lock);
 	idx = 0;
 	for_each_netdev(&init_net, dev) {
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
index 204d4d6..b9b5d57 100644
--- a/net/ipv6/addrlabel.c
+++ b/net/ipv6/addrlabel.c
@@ -361,12 +361,16 @@ static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
 static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
 			     void *arg)
 {
+	struct net *net = skb->sk->sk_net;
 	struct ifaddrlblmsg *ifal;
 	struct nlattr *tb[IFAL_MAX+1];
 	struct in6_addr *pfx;
 	u32 label;
 	int err = 0;
 
+	if (net != &init_net)
+		return 0;
+
 	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
 	if (err < 0)
 		return err;
@@ -445,11 +449,15 @@ static int ip6addrlbl_fill(struct sk_buff *skb,
 
 static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	struct ip6addrlbl_entry *p;
 	struct hlist_node *pos;
 	int idx = 0, s_idx = cb->args[0];
 	int err;
 
+	if (net != &init_net)
+		return 0;
+
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
 		if (idx >= s_idx) {
@@ -479,6 +487,7 @@ static inline int ip6addrlbl_msgsize(void)
 static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr* nlh,
 			  void *arg)
 {
+	struct net *net = in_skb->sk->sk_net;
 	struct ifaddrlblmsg *ifal;
 	struct nlattr *tb[IFAL_MAX+1];
 	struct in6_addr *addr;
@@ -487,6 +496,9 @@ static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr* nlh,
 	struct ip6addrlbl_entry *p;
 	struct sk_buff *skb;
 
+	if (net != &init_net)
+		return 0;
+
 	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
 	if (err < 0)
 		return err;
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 946cf38..31b60a0 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -361,6 +361,7 @@ end:
 
 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	unsigned int h, s_h;
 	unsigned int e = 0, s_e;
 	struct rt6_rtnl_dump_arg arg;
@@ -369,6 +370,9 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 	struct hlist_node *node;
 	int res = 0;
 
+	if (net != &init_net)
+		return 0;
+
 	s_h = cb->args[0];
 	s_e = cb->args[1];
 
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 4ef2cfa..5e1c579 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2003,9 +2003,13 @@ errout:
 
 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 {
+	struct net *net = skb->sk->sk_net;
 	struct fib6_config cfg;
 	int err;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	err = rtm_to_fib6_config(skb, nlh, &cfg);
 	if (err < 0)
 		return err;
@@ -2015,9 +2019,13 @@ static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *a
 
 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 {
+	struct net *net = skb->sk->sk_net;
 	struct fib6_config cfg;
 	int err;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	err = rtm_to_fib6_config(skb, nlh, &cfg);
 	if (err < 0)
 		return err;
@@ -2152,6 +2160,7 @@ int rt6_dump_route(struct rt6_info *rt, void *p_arg)
 
 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
 {
+	struct net *net = in_skb->sk->sk_net;
 	struct nlattr *tb[RTA_MAX+1];
 	struct rt6_info *rt;
 	struct sk_buff *skb;
@@ -2159,6 +2168,9 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
 	struct flowi fl;
 	int err, iif = 0;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
 	if (err < 0)
 		goto errout;